1的单词是one.

one：

num./det.一;(正式用语或表强调，用在hundred、thousand等或度量单位之前)一;(表强调)单独一个，仅仅一个。

pron.用来避免重复已提过的或是听者已知的事物的名称;用于辨别所谈的人或事;其中的一个人(或事物)。

复数：ones.

相关介绍

There is, in addition, one further point to make.

还有一点要说。

This is one of the most commonly used methods.

这是最常采用的方法之一。

This is too big ─ have you got a small one?

这个太大——有没有小的？

The system was introduced on a trial basis for one month.

这个制度已引进试行一个月。

It's been quite a day, one way and another.

从几方面看，这是不寻常的一天。

There were more than 50 people on stage in one scene.

有一场戏中舞台上的人有50多个。

One major problem did present itself, though.

不过，确实出现了一个重大问题。

Happy New Year to one and all!

祝各位新年快乐！